Extraction, determination and evaluation the anti-virulence compounds of Citrus aurantium against multi-drug resistant Staphylococcus aureus

Citrus aurantium L., sometimes referred to as the bitter or sour orange, is a member of the Rutaceae family (order Sapindales) and is indigenous to a large region of Asia (from northern China to India) and Oceania (Queensland, Australia). The present study aimed to investigate the anti-virulence compounds of C. aurantium extracts against S. aureus. Ethanol extract showed good activity against S. aureus at concentration (20 mg/ml), with inhibition zone diameter (24.5 mm) and lowest MIC value (2.5 mg/ml), and the least activity was recorded by acetone extract giving 12 mm inhibition zone diameter with the highest MIC value (5 mg/ml). While propanol extract showed mild antibacterial activity. The ethanol extract showed stronger effect than acetone and propanol extracts on hemolytic activity of S. aureus at different concentrations (0.625, 125, 250, 500, 1000 and 2000 μg/ml). The best fractionation of ethanol extract was dichloromethane that effect on hemolytic activity and protease production of S. aureus at concentration (1000 μl/mg). Dichloromethane fraction was utilized for gas chromatography-mass spectrometry (GCMS) analysis.